neurotransmission is a process that sees different chemicals released across a synapse between two neurons that can affect behaviour or mood

neurotransmitters are chemicals that travel across a synapse that are released in the brain that can affect the behaviour or mood of an individual

acetylcholine (excitatory [increase likelihood that neuron will fire second action potential in post- neuron] , used in spatial memory)

serotonin (inhibitory [decreased likelihood of second action potential] , involved in emotion and mood and regulates processes)

neurotransmitters travel across the synaptic cleft (gap between pre and post-synaptic neuron), neuron is activated by action potential which allows vesicles to move, fuse to pre- membrane and release neurotransmitters across cleft, receptors on post- absorb neuro- and these can then be excited by a second action potential

to determine the role of acetylcholine in the formation of spatial memory

highly controlled conditions where accurate measurements are possible, participants randomly allocated to the IV

30 rats acclimate to a Hebb Williams maze by placing food in one of the corners. Rats randomly allocated to one of two conditions: injected with scopolamine (blocks acetylcholine receptors) or saline solution (placebo, control) directly into the hippocampus 10 minutes before running the maze. Encoding of memory (STM) assessed by average errors made on first 5 trials on day 1 compared to last 5 on day 1. Average number on errors made in first 5 trials compared to last 5 on day 2 to assess retrieval (LTM)

scopolamine group (experimental) took longer and made more mistakes in learning of the maze however did not appear to have an effect on retrieval

Rogers and Kesner demonstrate the effect of acetylcholine on visuo-spatial memory. For example, the rats injected with scopolamine made more mistakes on day 1 in comparison to the rats injected with a saline solution. This is important because it shows that acetylcholine is needed for the encoding (formation) of visuo-spatial memory as an excitatory neurotransmitter in the brain. Therefore, neurotransmitters have an effect on behaviour.

high internal validity; the controlled variables, hebb williams maze

low mundane realism; hebb williams maze is not a usual activity for rats, however they do navigate sewers etc

to investigate changes in brain function of depressed subjects during treatment with placebo

51 patients with depression who either received placebo or an active antidepressant medication. as EEG was used to compare brain function in the two experimental groups, design was double-blind (participants nor examiner knew who received what) and ran over 9 weeks (2-4 weeks to work). Two SSRIs (antidepressants) randomly allocated to participants

placebo group = significant increase in prefrontal cortex (emotion) activity nearly from beginning, SSRIs group different pattern but both groups got better

Leuchter demonstrates the role of serotonin on mood. For example, the depressed patients who took SSRIs, which increase the uptake of serotonin, experienced a decrease in depressive symptoms. This is important because it supports the idea that serotonin regulates mood and therefore that neurotransmitters have an effect on behaviour as patients who took SSRIs got better. Therefore, neurotransmitters have an effect on behaviour